In general, a draw-out type circuit breaker is connected in an electric circuit between a power supply and a load, and is a type of breaker used to allow a main circuit current to flow and shut it out. The draw-out type circuit breaker is used in a state in which it is accommodated and fixed in a power distribution board.
The draw-out type circuit breaker is substantially structured with a main contact that closes and opens a main circuit, a driving apparatus that drives the main contact, a main circuit energizing part that allows a main circuit current to flow, a connecting part that enables the main circuit energizing part in the draw-out type circuit breaker and a portion of the main circuit in the power distribution board to be removably connected to each other, a moving device that moves the draw-out type circuit breaker, an interlock device that fixes the draw-out type circuit breaker accommodated in the power distribution board at an appropriate position, and the like.
During an operation, the draw-out type circuit breaker is usually fixed by the interlock device at an operation position at which the main circuit portion in the power distribution board and the draw-out type circuit breaker are appropriately connected to each other by the connecting part.
Accordingly, the connecting part of the main circuit portion in the power distribution board and the draw-out type circuit breaker, the energizing part, and the main contact constitute the main circuit. When the main contact of the draw-out type circuit breaker is closed and opened, electric power is supplied from the power supply to the load or is shut out.
A conventional interlock device is described in PTL 1. The interlock device described in PTL 1 has an interlock rod, an interlock switch, a control circuit board, and the like. The interlock device is characterized in that the interlock switch forcibly shuts off a closing command to be input to the control circuit board according to the operation of the interlock rod.